This invention relates to compounds having the generic structure: ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different and each represents hydrogen or C1-C3 lower alkyl, processes for preparing same and organoleptic uses thereof in perfumes, colognes, perfumed articles such as anionic, cationic and nonionic detergents and dryer-added fabric softeners and in smoking tobaccos and smoking tobacco articles which comprise a wrapper encasing a smoking tobacco body and impinging thereupon a smoking tobacco article filter.
There has been considerable work performed relating to substances which can be used to impart (modify, augment or enhance) flavors and fragrances to (or in) various consumable materials. These substances are used to diminish the use of natural materials, some of which may be in short supply, and to provide more uniform properties in the finished product.
Low-keyed, oily, woody amber, leathery, warm spice, earthy, camphoraceous, patchouli-like, balsamic, green, cardamom-like, vetiver-like, sweet woody, amber and minty aromas are desirable in several types of perfume compositions, perfumed articles such as anionic, cationic and non-ionic detergents, cosmetic powders and dryer-added fabric softener articles, and colognes.
Sweet, floral, woody, spicy, leathery and amber aromas prior to smoking and sweet, natural tobacco-like tastes and aromas are desirable in several types of smoking tobaccos, smoking tobacco articles and in smoking tobacco flavoring compositions.
British Pat. No. 896,039 entitled "Method of Producing Derivatives of the 1,1-Dimethyloctahydroaphthalene Series" discloses the generic process: ##STR3## wherein R.sub.2, R.sub.3, and R.sub.4 are disclosed to be same or different hydrogen atoms or alkyl and R.sub.1 is disclosed to be hydroxy, alkyl or alkoxy. The British patent discloses this process to be useful for producing products "resembling the well known class of violet perfumes". Indeed, Example 5 of the British patent alleges that the compound 1,1,6,6-Tetramethyl-7-ketomethyl-Octalin produced by (1) reacting myrcene and mesityl oxide thermally followed by (2) subsequent cyclization, has a pleasant "woody ambergris smell". However, a repetition of the teachings of this British patent gives rise to the following results: ##STR4##
U.S. Pat. No. 2,933,506, issued on Apr. 19, 1960, discloses the production of perfume compounds according to the reaction sequence: ##STR5##
In said formula R.sub.1, R.sub.2, R.sub.3, and R.sub.4 represent hydrogen or alkyl, especially a lower alkyl radical, aryl, aralkyl, cycloalkyl, or heterocyclic residues. R.sub.1 in said formula can also be the hydroxyl group or an ether group. The ether group may form an ester group or a lactone group with the --CO-- group.
The new compounds are obtained by first subjecting myrcene of Formula I to the diene synthesis with a dienophillic compound of Formula II. The resulting adduct of Formula III is then subjected to ring closure reaction to form the corresponding 1,1-dimethyl octaline compounds of Formula IV.
Thus, for example, the 1,1-dimethyl-7-methylal octaline can be produced as follows:
576 g. (3 mols) of the aldehyde obtained from myrcene and acrolein, said aldehyde corresponding to Formula III wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are hydrogen, are dissolved in 600 cc. of ether. 279 g. (3 mols) of aniline dissolved in 500 cc. of ether are added to said solution portion by portion at room temperature in a separatory funnel while shaking the mixture repeatedly.
After allowing the mixture to stand at room temperature for about 20 hours, the theoretical amount of water has split off. The resulting solution is separated from the water formed on reaction and is directly used for cyclization.
The ethereal solution of the Schiff's base is added drop by drop to 4 l. of 62% sulfuric acid at -15.degree. C. within about 2 hours while stirring vigorously. Care must be taken that the temperature does not substantially exceed 0.degree. C. After the solution has been added to the sulfuric acid, stirring of the reaction mixture is continued at -5.degree. C. for about one hour. The reaction mixture is then treated with steam until all the solvent has been distilled off. The distillation requires about 1/2 hour. The reaction mixture has now separated into two layers. It is poured on ice and is exhaustively extracted with benzene. The benzene solution of the bicyclic aldehyde is washed with water until the wash water is substantially neutral. Thereafter, the solvent is distilled off under atmospheric pressure and the residue is subjected to fractional distillation in a vacuum.
In this manner 438 g. of 1,1-dimethyl-7-methylal octaline are obtained. The yield is about 76% of the theoretical yield. The reaction product consists to 2/3 of the .beta.-compound with the double bond in 9,10-position and to 1/3 of a substantially uniform isomer, the double bond of which is either in .alpha.-, or in .gamma.-, or in .delta.-position.
Characteristic properties of the mixture of isomers:
Boiling point: 85.degree.-86.degree. C./0.5 mm.;
Density d.sub.4.sup.20 : 0.9877;
Index of refraction n.sub.D.sup.20 : 1.5031;
Aldehyde content: 98-100%.
By fractional crystallization of the semicarbazones of the reaction mixture the isomers can be separated from each other. For this purpose 70 g. of the bicyclic aldehyde mixture are mixed with a solution of 70 g. of semicarbazide hydrochloride and 70 g. of sodium acetate in 140 cc. of water. Methanol is added until complete solution is achieved. The reaction mixture is allowed to stand overnight at room temperature. 95.5 g. of an amorphous semicarbazone precipitates. It has an unsharp point of decomposition at 139.degree.-141.degree. C. On repeated recrystallization from 90% methanol, 53.5 g. of white crystals melting at 148.degree. C. with decomposition are obtained.
In order to produce therefrom pure 1,1-dimethyl-7-methylal-.DELTA..sub.9,10 -octaline, the semicarbazone was split up by heating with 50 g. of oxalic acid in 200 cc. of water. The aldehyde set free thereby is separated from the reaction solution by vacuum steam distillation. The steam distillate is subjected to fractional distillation in a vacuum. In this manner 30 g. of a very pure aldehyde are obtained. This aldehyde has a pleasant refreshing and sandalwood-like ionone odor.
Characteristic properties of 1,1-dimethyl-7-methylal-.DELTA..sub.9,10 -octaline:
Boiling point: 85.degree. C./0.5 mm.;
Density d.sub.4.sup.20 : 0.9914;
Index of refraction n.sub.D.sup.20 : 1.5054;
Aldehyde content: 100%.
After standing for several days at -25.degree. C. there precipitates from the mother liquor of the semicarbazone reaction mixture a second compound which, on repeated recrystallization from methanol, has a melting point of 134.degree. C. 14.5 g. of this semicarbazone are obtained. The aldehyde is set free therefrom by means of oxalic acid in the same manner as described hereinabove for the .beta.-aldehyde.
The position of the double bond in said aldehyde could not yet be ascertained with certainty. The double bond is either in .alpha.-, .gamma.-, or .gamma.-position. The compound also has a refreshing ionone aroma, however, without any accompanying sandalwood-like nuance.
Characteristic properties of this isomeric aldehyde:
Boiling point: 85.degree.-86.degree. C./0.5 mm.,
Density d.sub.4.sup.20 : 0.9890;
Index of refraction n.sub.D.sup.20 : 1.5044;
Aldehyde content: 100%.
Another example indicating preparation of 1,1-dimethyl-7-methylal octaline in U.S. Pat. No. 2,933,506 is as follows:
1 mol. of the aldehyde in the form of its Schiff's base as prepared and used in Example 1 is dissolved in an equal amount of benzene. The benzene solution is added drop by drop to 700 cc. of 85% phosphoric acid at 0.degree. C. while stirring vigorously. Thereafter, stirring of the reaction mixture is continued at 60.degree. C. for 1 hour. Thereby not only cyclization is completed but the azomethine group is quantitatively split up. The resulting bicyclic aldehyde is then poured on ice, extracted by means of benzene, and the benzene layer is washed with water until neutral. After distilling off the solvent, 190 g. of residue of an aldehyde content of 82% are obtained. The crude bicyclic aldehyde is subjected to fractional distillation by means of a small fractionating column. In this manner 135 g. of 1,1-dimethyl-7-methylal octaline are obtained. The yield is about 70% of the theoretical yield. The aldehyde consists mainly of an isomer, the double bond of which is either in .alpha.-, or in .gamma.-, or in .delta.-position.
Characteristic properties:
Boiling point: 96.degree. C./0.7 mm.;
Density d.sub.4.sup.20 : 0.9884;
Index of refraction n.sub.D.sup.20 : 1.5042;
Aldehyde content: 98-100%.
Additional reaction of the resulting compounds with acid and heating gives rise to the compounds of our invention having the generic structure: ##STR6## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different and each represents hydrogen of C1-C3 lower alkyl.
However, there is no inference in any of the pertinent prior art that the tricyclic ketone compounds of our invention can be produced or ever have been produced.